diff --git a/2020/10/main.py b/2020/10/main.py
index db3c920..dc572cc 100644
--- a/2020/10/main.py
+++ b/2020/10/main.py
@@ -1,120 +1,45 @@
 import copy
+from collections import Counter
 
 
 def load(filename):
 	with open(filename, "r", encoding="utf-8") as f:
-		return [int(x) for x in f]
-
-
-def calc_builtin(adapters):
-	return max(adapters) + 3
+		r = sorted([int(x) for x in f])
+		r.insert(0, 0)
+		r.append(r[-1] + 3)
+		return r
 
 
 def calc_diffs(adapters):
-	wall = 0
-	builtin = calc_builtin(adapters)
-	adapters = sorted(adapters)
-	adapters.insert(0, 0)
-	adapters.append(builtin)
-	adapters += [wall, builtin]
-
-	d1 = 0
-	d2 = 0
-	d3 = 0
-	sa = sorted(adapters)
-	for x in range(0, len(sa) - 1):
-		a = sa[x]
-		b = sa[x+1]
-		d = b - a
-		if d == 1:
-			d1 += 1
-		elif d == 2:
-			d2 += 1
-		elif d == 3:
-			d3 += 1
-
-	return d1, d2, d3
+	c = Counter()
+	for i in range(len(adapters) - 1):
+		d = adapters[i+1] - adapters[i]
+		c[d] += 1
+	return c
 
 
-def is_compatible(a, b):
-	return abs(a - b) <= 3
+def calc_total(adapters):
+	c = Counter()
+	c[0] = 1
+	for a in adapters:
+		for i in range(1, 4):
+			c[a] += c[a-i]
+	return c[adapters[-1]]
 
 
-def calc_arrangements(adapters, wall, builtin):
-	return _calc(sorted(adapters), [wall], builtin)
-
-def _calc(adapters, arranged, builtin):
-	a = arranged[-1]
-	b = adapters.pop(0)
-	while is_compatible(a, b):
-		if not adapters:
-			if is_compatible(b, builtin):
-				yield arranged + [b, builtin]
-			return
-
-		cadapters = copy.deepcopy(adapters)
-		carranged = copy.deepcopy(arranged)
-		carranged.append(b)
-		yield from _calc(cadapters, carranged, builtin)
-
-		b = adapters.pop(0)
-
-
-assert calc_builtin([3, 6, 9]) == 12
-
 adapters = load("test1.txt")
-d1, _, d3 = calc_diffs(adapters)
-assert d1 == 7
-assert d3 == 5
+c = calc_diffs(adapters)
+assert (c[1], c[3]) == (7, 5)
+assert calc_total(adapters) == 8
 
 adapters = load("test2.txt")
-d1, d2, d3 = calc_diffs(adapters)
-assert d1 == 22
-assert d3 == 10
-print(d1, d2, d3)
+c = calc_diffs(adapters)
+assert (c[1], c[3]) == (22, 10)
+assert calc_total(adapters) == 19208
 
 adapters = load("data.txt")
-d1, _, d3 = calc_diffs(adapters)
-print(f"1: Answer is {d1 * d3}")
+c = calc_diffs(adapters)
+print(f"1: Answer is {c[1] * c[3]}")
 
-##############################################################################
-
-assert d1*d3 == 2450, "Task 1"
-
-adapters = load("test1.txt")
-bi = calc_builtin(adapters)
-arrangements = list(calc_arrangements(adapters, 0, bi))
-assert [0, 1, 4, 5, 6, 7, 10, 11, 12, 15, 16, 19, 22] in arrangements
-assert [0, 1, 4, 5, 6, 7, 10, 12, 15, 16, 19, 22] in arrangements
-assert [0, 1, 4, 5, 7, 10, 11, 12, 15, 16, 19, 22] in arrangements
-assert [0, 1, 4, 5, 7, 10, 12, 15, 16, 19, 22] in arrangements
-assert [0, 1, 4, 6, 7, 10, 11, 12, 15, 16, 19, 22] in arrangements
-assert [0, 1, 4, 6, 7, 10, 12, 15, 16, 19, 22] in arrangements
-assert [0, 1, 4, 7, 10, 11, 12, 15, 16, 19, 22] in arrangements
-assert [0, 1, 4, 7, 10, 12, 15, 16, 19, 22] in arrangements
-
-adapters = load("test2.txt")
-bi = calc_builtin(adapters)
-arrangements = list(calc_arrangements(adapters, 0, bi))
-assert [0, 1, 2, 3, 4, 7, 8, 9, 10, 11, 14, 17, 18, 19, 20, 23, 24, 25, 28, 31, 32, 33, 34, 35, 38, 39, 42, 45, 46, 47, 48, 49, 52] in arrangements
-assert [0, 1, 2, 3, 4, 7, 8, 9, 10, 11, 14, 17, 18, 19, 20, 23, 24, 25, 28, 31, 32, 33, 34, 35, 38, 39, 42, 45, 46, 47, 49, 52] in arrangements
-assert [0, 1, 2, 3, 4, 7, 8, 9, 10, 11, 14, 17, 18, 19, 20, 23, 24, 25, 28, 31, 32, 33, 34, 35, 38, 39, 42, 45, 46, 48, 49, 52] in arrangements
-assert [0, 1, 2, 3, 4, 7, 8, 9, 10, 11, 14, 17, 18, 19, 20, 23, 24, 25, 28, 31, 32, 33, 34, 35, 38, 39, 42, 45, 46, 49, 52] in arrangements
-assert [0, 1, 2, 3, 4, 7, 8, 9, 10, 11, 14, 17, 18, 19, 20, 23, 24, 25, 28, 31, 32, 33, 34, 35, 38, 39, 42, 45, 47, 48, 49, 52] in arrangements
-assert [0, 3, 4, 7, 10, 11, 14, 17, 20, 23, 25, 28, 31, 34, 35, 38, 39, 42, 45, 46, 48, 49, 52] in arrangements
-assert [0, 3, 4, 7, 10, 11, 14, 17, 20, 23, 25, 28, 31, 34, 35, 38, 39, 42, 45, 46, 49, 52] in arrangements
-assert [0, 3, 4, 7, 10, 11, 14, 17, 20, 23, 25, 28, 31, 34, 35, 38, 39, 42, 45, 47, 48, 49, 52] in arrangements
-assert [0, 3, 4, 7, 10, 11, 14, 17, 20, 23, 25, 28, 31, 34, 35, 38, 39, 42, 45, 47, 49, 52] in arrangements
-assert [0, 3, 4, 7, 10, 11, 14, 17, 20, 23, 25, 28, 31, 34, 35, 38, 39, 42, 45, 48, 49, 52] in arrangements
-assert len(arrangements) == 19208
-
-#adapters = load("data.txt")
-#bi = calc_builtin(adapters)
-#
-#arrangements = calc_arrangements(adapters, 0, bi)
-#c = 0
-#for x in arrangements:
-#	print(x)
-#	c += 1
-#
-#print(f"2:Found {c} ways to connect.")
+c = calc_total(adapters)
+print(f"2: Answer is {c}")